1. Field of the Invention
This invention relates generally to devices for generating power from vertical motion and, more particularly, to an apparatus for generating power from the vertical motion of ocean waves.
2. Technical Background
Vertical motion wave power generators for producing electricity from ocean waves are known. It has been effective to use one-way clutches to convert the up and down vertical motion of waves into unidirectional rotary motion to turn an electric generator. However, existing devices have been too complex, or insufficiently durable, or too small to be practical or of commercial value.
U.S. Pat. No. 5,105,094 discloses a stationary wave generator that operates by moving a piston up and down in a cylinder. The piston engages a drive through a rack and pinion gear system which then engages a unidirectional rotary power shaft. The rotary power shaft and generator are fixed and do not float up and down. The rack and pinion arrangement is subject to excessive wear. The piston and cylinder need constant maintenance and there needs to be a draining regulation mechanism. The device is useful only for shore waves and a large number of units would be required to produce sufficient power.
U.S. Patent Application No. 2006/0232074 discloses a stationary wave generator that uses a float and lever with a linkage system to drive a drive shaft clockwise and counterclockwise. The drive shaft engages a power shaft so as to rotate it in one direction. The float and lever system, with the linkage to a stationary generator, is susceptible to damage due to the force of waves. The flotation capacity of the float in this system is small and many units would be required to produce sufficient power.
U.S. Pat. No. 6,476,512 describes a stationary wave generator that moves a float up and down in a tall tower. Five different rotating shafts in this system are required to convert the up and down vertical motion of the float into unidirectional rotational motion. The float is relatively small so that many units would be required to produce sufficient power.
U.S. Patent Application No. 2006/0028026 discloses a stationary wave generator that captures only the upward force of a wave using a plurality of worm gears and rack and pinion gears. The system has low total buoyancy.
U.S. Pat. No. 7,315,092 discloses a floating wave generator in which the generator portion is connected by arms to two floats which move up and down in a direction opposite to that of the generator portion. One of the floats turns a drive shaft clockwise and counterclockwise. The drive shaft engages a power shaft so as to rotate it in one direction. The constant opposing motion between the floats and the generator create problems of wear and insufficient durability. There is no capacity for a flywheel in this system which is usually required with the use of one-way clutches. The system is inherently limited in size and many units would be required to produce sufficient power.
U.S. Pat. No. 4,539,484 discloses a floating wave generator system in which the generator system is attached to a float which moves up and down with the motion of waves. The float is confined within a frame which is connected to the ocean bottom. Cables are connected to the frame below and above the float. The central portions of the cables are wound several times around drums to rotate the drums clockwise and counterclockwise as the float moves up and down with the motion of the waves. One-way clutches are attached to each end of the drums. A plurality of reversing gears and worm gears are used to convert the clockwise and counterclockwise rotation of the drums into unidirectional rotation. A third over-running clutch is required to transfer the unidirectional rotation to an electric generator. The cable that is wound around the drum is subject to considerable friction which causes undue wear on the cable and the drum. The plurality of reversing gears and worm gears also causes undue friction, wear, and maintenance. The float is relatively difficult to disengage from the frame when it is necessary to remove the float to a harbor, such as during a storm or for repair.
What is needed, but which has never been available, is a system in which the generator is attached to a float and moves up and down with the float to prevent wear, tear, and damage; up and down motion is converted to unidirectional rotary motion with a single power shaft without the need for a plurality of intervening power shafts and gears so that the system is durable and requires little maintenance and repair; the power generating capacity of the system can be equal to that of a nuclear power plant; and the flotation system is easy to disengage from a support frame structure for transport.